When the federal government was small, it thought big.

Indeed, it focused exclusively on big issues. For example, when the Constitution was written, it listed only three federal crimes. Today there are more than 4,000.

Where once our national government concerned itself with preventing only counterfeiting, piracy and treason, it's now involved in measuring the length of lobster tails and prosecuting importers if those tails are too short. All this is a relatively new development. Almost half of all federal crimes have been added to the criminal code since 1970.

And Congress may be about to make this bad situation even worse.

Recently the House of Representatives approved a gang deterrence measure. The Senate is considering a similar bill. Either would make a number of gang-related crimes federal offenses.

Now, we're all opposed to gang violence. But let's remember that such activity -- shooting, drug running, gun trafficking -- already is illegal in every state. Turning gangland violence into a federal offense doesn't guarantee we'll have less violence; it simply means we'll be trying defendants in a different venue.

Such measures are usually just a way for federal lawmakers to look effective. They pass a law, can say they've "solved" a problem, and move on. But the federalization of the law has real consequences.

For example, most would agree that the FBI is stretched thin these days. But instead of focusing on real national law-enforcement priorities, federal agents spend too much time and effort investigating crimes that should be left to local and state officers. If we make gang violence a federal crime, that trend will only worsen.

Meanwhile, local officials get a free pass. With cases being moved to federal court, the responsibility for prosecuting criminals shifts to U.S. attorneys, so local police and prosecutors get left out of the process. We shouldn't be undermining local officials. We should be empowering them to crack down on criminals.

A closer look at the Senate bill reveals two key provisions that are particularly bad.

The first provision, Section 201, would be a major step toward turning all double murders into federal crimes. It would become a federal offense to kill someone, cross a state line and kill someone else. Of course, such killings are illegal already and in many states are punishable by death. It's difficult to see how making double murder a federal offense would deter anyone.

In fact, this measure seems to be aimed specifically at John Allen Muhammad. He and his associate Lee Boyd Malvo allegedly used a sniper's rifle to kill people in Maryland, Virginia and the District of Columbia in 2002. But the Muhammad case actually proves there's no need for another law.

He's already been convicted of murder in Virginia and sentenced to death. While on death row, he may face further charges in Maryland. Malvo, who was 17 at the time of the killings, has been handed a life sentence without the chance of parole. The system already has worked well, convicting these killers without any federal involvement.

Another provision of the bill would define a "criminal street gang" as any association of three or more people who attempt to commit two crimes within 10 years. One of those crimes is obstruction of justice, which of course is what landed Martha Stewart in prison. That means that, if anyone in her company were to be convicted of obstruction of justice in the years ahead, Martha Stewart Omnimedia could be considered a gang.

This bill also would have made Enron a gang, which is simply silly. That company may well have been a criminal enterprise, but it wasn't a criminal street gang.

Crime prevention truly begins at home. Throughout American history, local and state officials have investigated and tried most criminals. Let's keep it that way and free up federal officials to focus on truly national issues, such as protecting the homeland from terrorists.

Ed Feulner is president of the Heritage Foundation.